April 28, 2018

Odonata Life Stage Annotation

Based on Scott Loarie's suggestion following an inquiry, I am inviting the more active iNaturalist odonatists and a couple of admin types to a discussion regarding the life stage annotation options relating to Odonata. Annotations are kind of a new thing (introduced last fall?), and I think they can use some refinement at least with regard to odonates. The current life stage options for odonates are Egg, Nymph, Teneral, Adult.

Teneral

My biggest issue is with the Teneral option. Teneral is a condition following molt—not a stage in between nymph and adult. Odonates are teneral at the beginning of adulthood (not before adulthood) following their molt out of nymph-hood. This has led to some disagreements with other iNat users who insist that a particular odonate is Teneral, not Adult. An adult odonate is Adult, whether or not it is teneral. Have I beaten this dead horse sufficiently?

While the teneral description is most commonly used for adults immediately following their emergence, I point out that an odonate is teneral every time it molts from one nymph stadium to the next. So, an adult odonate has been teneral multiple times while it was a nymph, and then one final time when it became an adult. Another way to put it is that an odonate can be a nymph AND teneral as well as an adult AND teneral. I also have to point out that the teneral condition is experienced by all arthropods following molt. It's isn't limited to odonates, but I have only seen the Teneral annotation associated with odonate submissions on iNaturalist.

My recommendation is to drop the Teneral option from the life stage annotation for odonates (and any other arthropods for which it is an option). Any submissions which are currently annotated as Teneral, I would simply change to Adult. Personally, I don't see the value of annotating teneral adults differently from other adults, but if anyone does perhaps options like "Adult (teneral)" and "Adult (mature)" make sense. But, again, I don't see the value of doing so, especially since it can be a rather subjective call.

Exuviae

Here's another category that I ponder, although I don't have a solid recommendation. For those submissions which are based on exuviae only—the vacant nymphal "skin" left behind following emergence (here's an example: https://www.inaturalist.org/observations/1600819), what is the best way to annotate them?

Visually/structurally exuviae are nymph-like, and since nymphal characters are used to identify exuviae, I can see annotating them with Nymph. However, viewing such a submission strictly through the lens of life stage, the Adult annotation could make sense since the individual that left its "nymph suit" behind has moved on to adulthood (and is presumably flying around somewhere). On the other hand, during periods of no precipitation or in some sheltered situations (like under a bridge), exuviae can persist beyond the adult life span of the individual that left it behind.

Perhaps an additional category of "Exuviae" make sense to distinguish it from Nymph and Adult, even though it isn't really a life stage. I guess this makes the most sense to me although I'm agnostic on it, and I'm particularly interested in opinions (more so than the Teneral topic). Like the teneral condition, exuviae is a general arthropod thing not limited to odonates.

Any thoughts? @greglasley @briangooding @nlblock @aguilita @vicfazio3 @sambiology @scottking @ericisley @cordulegaster @joshualincoln @jcabbott @loarie @kueda

Posted on April 28, 2018 23:48 by jimjohnson jimjohnson | 12 comments | Leave a comment

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